What Happens When You Lack Manganese? A Comprehensive Guide

December 29, 2025 •

4 min read

While true clinical manganese deficiency in otherwise healthy humans is rare, occurring most notably in experimental or clinical settings, its effects can be significant. This trace mineral is essential for vital bodily functions, and its depletion can lead to a variety of serious health issues impacting bone, metabolism, and the nervous system.

Quick Summary

A lack of manganese can trigger skeletal defects, impaired growth, metabolic and reproductive issues. Though rare, deficiency affects antioxidant function, bone density, and can cause neurological and mood-related symptoms.

Key Points

Rarity: True clinical manganese deficiency is very rare in healthy individuals, with most risk factors tied to underlying medical conditions or restricted diets.
Skeletal Health: A lack of manganese can cause poor bone growth, decreased bone density, and severe skeletal defects, especially concerning during development and in older adults.
Metabolic Impact: Deficiency can impair glucose tolerance and disrupt the metabolism of carbohydrates and fats, potentially affecting insulin production and regulation.
Antioxidant Function: Manganese is a key component of the antioxidant enzyme SOD, and its deficiency weakens the body's defense against damaging free radicals.
Reproductive Issues: Inadequate manganese levels may be linked to impaired fertility in both men (affecting sperm quality) and women (affecting ovulation).
Neurological and Mood Symptoms: Although more common with toxicity, a deficiency can potentially cause mood changes, altered nerve signaling, and, in severe cases, neurological symptoms.
Diagnosis Challenges: Diagnosing deficiency is difficult because blood tests can be unreliable due to the body storing manganese in various tissues, including the bones and liver.

The Core Functions of Manganese in the Body

Manganese is an essential trace mineral required for the proper functioning of numerous enzymes that catalyze crucial metabolic processes. It acts as a cofactor in the metabolism of carbohydrates, amino acids, and cholesterol, and is integral to the body's antioxidant defense system. A key role is as part of the enzyme superoxide dismutase (SOD), which helps neutralize damaging free radicals within the mitochondria, the body's energy-producing centers. It is also critical for bone and cartilage formation, collagen synthesis for wound healing, and maintaining normal reproductive and nervous system health.

Skeletal and Developmental Consequences

One of the most noticeable effects of a manganese shortage is on bone health and growth. In children, a deficiency can manifest as impaired growth and skeletal abnormalities, reflecting the mineral's role in bone development and maintenance. Animal studies provide more detail, showing that deficiency can cause severe skeletal defects, such as joint enlargement and shorter, thicker limbs. For adults, inadequate manganese may lead to decreased bone mineral density, potentially increasing the risk of osteoporosis, especially in postmenopausal women.

Metabolic Disturbances

Without sufficient manganese, your body's metabolic functions can go awry. Manganese is heavily concentrated in the pancreas and plays a part in insulin production and the regulation of blood sugar. Low levels have been linked to impaired glucose tolerance and abnormal metabolism of fats and carbohydrates. Research suggests that individuals with diabetes tend to have lower blood manganese levels, though the exact relationship is still under investigation.

Neurological and Nervous System Effects

While typically associated with manganese toxicity, certain neurological and mood-related symptoms have been observed in studies of manganese deficiency. Manganese is present in the brain and plays a role in nervous system function. Early human studies observed symptoms like altered mood and increased irritability. In severe cases, a deficiency could theoretically impact nervous system signaling, as the mineral assists with nerve impulse transmission.

Reproductive and Fertility Issues

Animal and limited human studies suggest a link between manganese levels and reproductive health. For men, deficiency can impact testicular function and sperm quality, potentially causing testicular degeneration and reduced sperm motility. In women, a diet low in manganese has been associated with an increased risk of anovulation (absence of ovulation), which can interfere with fertility. Animal models also show that pregnant females with a deficiency may give birth to offspring with coordination problems.

Other Symptoms of Manganese Deficiency

In addition to the primary issues, a lack of manganese can lead to other systemic problems, including:

Skin conditions like dermatitis and changes in hair color
Poor wound healing due to impaired collagen formation
Increased oxidative stress as the effectiveness of the SOD antioxidant enzyme is reduced
Increased premenstrual pain in women

Causes and Risk Factors for Manganese Deficiency

Though dietary deficiency is very rare for healthy individuals, certain factors can increase risk:

Poor Diet: Diets heavy in processed foods and low in manganese-rich whole foods like nuts, seeds, and leafy greens.
Malabsorption: Medical conditions such as exocrine pancreatic insufficiency, chronic liver disease, or gastric bypass surgery can hinder manganese absorption.
High Iron Intake: Excessively high iron intake can inhibit manganese absorption, as both minerals compete for the same transport pathways.
Other Conditions: People with certain conditions like epilepsy, osteoporosis, or diabetes may have lower-than-normal manganese levels.

Diagnosis and Treatment of Manganese Deficiency

Diagnosing manganese deficiency can be challenging due to the lack of standardized tests. Blood tests can measure manganese levels, but these can fluctuate and may not fully reflect long-term stores. Other diagnostic methods include a review of clinical symptoms, medical history, and diet.

If a deficiency is confirmed, treatment typically involves:

Dietary Changes: Increasing intake of manganese-rich foods such as whole grains, nuts, and leafy green vegetables.
Supplementation: A doctor may prescribe a manganese supplement, though self-treating with high doses is not recommended due to the risk of toxicity.
Addressing Underlying Conditions: For cases involving malabsorption, treating the primary medical condition is necessary for restoring normal levels.

Manganese Deficiency vs. Iron Deficiency: A Comparison


Feature	Manganese Deficiency	Iron Deficiency
Incidence	Very rare in healthy humans.	One of the most common mineral deficiencies globally.
Key Functions	Cofactor for metabolism, antioxidant enzymes (SOD), bone, and reproduction.	Crucial for hemoglobin production, oxygen transport, and muscle metabolism.
Skeletal Impact	Impaired bone formation, decreased density, and skeletal defects.	Can cause abnormal nail shapes and general weakness, not primary skeletal issues.
Metabolic Effects	Abnormal lipid and carbohydrate metabolism, impaired glucose tolerance.	Fatigue, weakness, cold hands/feet due to poor oxygen transport.
Reproductive Impact	Impaired fertility, testicular dysfunction, anovulation in women.	Anemia can impact reproductive function; specific impact differs.
Nervous System	Rare neurological or mood symptoms; potentially impaired nerve signaling.	Fatigue, dizziness, irritability; restless legs syndrome is a common symptom.
Interaction	Excess iron can inhibit manganese absorption.	Excess manganese can inhibit iron absorption, though not commonly a dietary concern.

Conclusion

Although a true lack of manganese is an uncommon occurrence in the general population, its role as a vital trace mineral is undeniable. When levels are insufficient, the cascade of enzymatic dysfunction can lead to serious health complications affecting the bones, metabolic processes, nervous system, and reproductive organs. Maintaining adequate intake through a balanced diet rich in whole foods is the primary way to prevent this deficiency, with supplementation only used under careful medical supervision due to the risks of toxicity. For those with underlying medical conditions that affect absorption, diagnosis and management by a healthcare professional are essential to restoring health. It is clear that while a low-profile mineral, manganese is nonetheless a critical component of overall wellness.

For more detailed information on manganese and its health effects, consult the National Institutes of Health (NIH) Health Professional Fact Sheet.

Frequently Asked Questions

The initial signs of manganese deficiency can include skin rashes, changes in hair color, and mood alterations, though these are often subtle and a clinical deficiency in healthy individuals is very rare.

To prevent manganese deficiency, consume foods like whole grains (e.g., brown rice), nuts (pecans, pine nuts), seeds, leafy green vegetables (spinach, kale), legumes, and certain spices like black pepper.

Manganese is essential for cartilage and bone formation. A deficiency can potentially contribute to joint issues and inflammation, and manganese has been studied in conjunction with glucosamine and chondroitin for osteoarthritis pain.

While blood tests can measure manganese levels, diagnosing deficiency can be challenging. Manganese levels can fluctuate in the blood and may not accurately reflect the body's long-term stores, which are predominantly in the bones and liver.

Excessive intake of manganese, especially via supplements, can be toxic and lead to neurological damage known as manganism, with symptoms resembling Parkinson's disease, including tremors and impaired motor skills.

Treatment involves dietary modification to include more manganese-rich foods, and in clinically diagnosed cases, a healthcare provider may recommend specific manganese supplementation. It is crucial to monitor intake to avoid toxicity.

Yes, a deficiency can disrupt the metabolism of carbohydrates and lipids. Manganese is a cofactor for enzymes involved in these metabolic pathways and is also linked to insulin production.